Error in re-building vignettes:
  ...
Loading required package: zoo

Attaching package: 'zoo'

The following objects are masked from 'package:base':

    as.Date, as.Date.numeric

Warning in validityMethod(object) :
  tracks with overlapping time intervals: 1
Warning in validityMethod(object) :
  tracks with overlapping time intervals: 1
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Found more than one class "xts" in cache; using the first, from namespace 'spacetime'
Also defined by 'quantmod'
Error in texi2dvi(file = file, pdf = TRUE, clean = clean, quiet = quiet,  : 
  Running 'texi2dvi' on 'article.tex' failed.
LaTeX errors:
! LaTeX Error: Option clash for package xcolor.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
Calls: buildVignettes -> texi2pdf -> texi2dvi
Execution halted